iMovie turns your vacation clips into a story, with smart tools that show your location and good-looking themes.Photo by Screenshot by Jason Parker/CNET

iMovie started out on the Mac, and the desktop is still the best place to create movies, but the slimmed-down iOS version of iMovie ($4.99) keeps getting better with added features that bring something more to your clips.

The big new addition to the app is the capability to make fun trailers for your movies. While you might wonder why you would want a trailer for your vacation movie, once you make one using the included themes, you'll see just how charming they can be.

Turning your regular videos into high-drama video trailers is fun and easy with the new trailer maker.Photo by Screenshot by Jason Parker/CNET

You can choose from several trailer types that run the gamut of movie genres, including adventure, horror, romance, and more, for a total of nine different themes. From there, iMovie offers a Story Board view that lets you add your own clips to fill out the premade trailer template, and you can edit text that shows up between the clips. Then you can switch to Outline view to customize movie studio logos, cast names, and credits. What results is a fun and professional-looking trailer with music that adds another layer of drama to your video clips.

Another new feature in iMovie is the ability to change and view music in sound effects in the Audio Browser. In addition to the music found in each theme, you can add music from your music library, and choose from more than 60 sound effects to add a little comedy to your clips. If you're using the iPad version, you can view color-coded audio waveforms for every clip, ensuring that levels match up in your finished project.

Some of the sound effects you'll recognize from your ringtone library, but there are plenty of others that will add comedy to your movies.Photo by Screenshot by Jason Parker/CNET

Once you're finished with your project, you can export the movie to your desktop computer or upload it to YouTube, Facebook, Vimeo, or CNN iReport. If you're not quite ready to post the movie to the world, you can share it in an e-mail, via iMessage, or use AirPlay to stream it to your HDTV over Wi-Fi if you have an Apple TV. If you want to do a little more-complex editing, you can also transfer your project to iMovie on your Mac.

iMovie isn't meant to be a pro-level video app for complex editing and feature-length motion pictures, but it is a great app to have on your iPhone or iPad to make nice-looking projects that are easy to share. These new additions and updates to the app add a few more ways to have fun with video and make it worth the $4.99 price tag.